The National Health Service "is in mortal danger" in its 70th birthday year and needs investment to survive, former prime minister Gordon Brown has said.

Mr Brown said the NHS was the "greatest British institution we've created" but was under threat from a period of investment rising "slower than any other decade" since its 1948 launch.

He said before the free at point of use health service was set up, "doctors having to check people's wallets before they were checking pulses", but it was now being "starved" of resources.

The former MP said there was not a person or a family in the country which had not seen first-hand its life-saving benefits - including himself.

Speaking to Labour supporters in a social club in Birmingham on Monday, he said: "In my own case, I'll be honest, I would have been blind without the NHS."

The former PM - in power from 2007 until 2010 - said: "The National Health Service is there when you need it."

Setting out his own record in government, first as chancellor and then as Prime Minister, he said Labour's 1% national insurance hike in 2002 had meant more doctors and nurses and "waiting lists down".

He also defended the private finance initiative (PFI) of building and maintaining hospitals, adding the number of new hospitals simply would not have got built without it.

Addressing about 300 people, he said: "Over these 70 years we have a health service that has remained free for almost all the essential treatments that are available, a health service that is universal."

But turning to the central theme of his 20-minute speech, Mr Brown spoke of the health service being "starved" of investment.

He said: "I'm afraid in 2018, the health service is in mortal danger again."

"And of course we still have the issue of how we finance elderly care because we cannot leave the elderly population of this country where they have to throw away all their savings simply to get the care that was needed at the end of their lives," Mr Brown added.